DESCRIPTION

Adiponectin, also known as Acrp30, AdipoQ, and GBP28, is an adipocyte-secreted protein that circulates in high concentrations in the serum and acts to increase insulin sensitivity. Adiponectin modulates a number of metabolic processes, including glucose regulation and fatty acid oxidation. The serum concentration of adiponectin decreases in obese patients, opposite to other adipocytokines. In recent studies, serum adiponectin level progressively decreased in patients according to the severity of obesity, insulin resistance, diabetes mellitus and cardiovascular diseases. Low serum adiponectin level may be a predictive factor for type 2 diabetes mellitus (T2DM) and other cardiovascular diseases.

PRINCIPLE OF THE ASSAY

An anti-tag antibody is pre-coated onto the bottom of wells. After adding antigen or samples, Tagged-Capture antibody and HRP-conjugated detection antibody, a sandwich complex is formed in the solution. TMB acts as a HRP substrate, and the solution color will change from colorless to blue. A stop solution containing sulfuric acid turns the solution yellow. The color intensity is proportional to the quantity of bound protein, which is measurable at 450 nm with the correction wavelength set at 630 nm.

PRECISION

Intra-assay Precision (Precision within an assay) Three samples of known concentration were tested 8 times on one plate to assess intra-assay precision. Inter-assay Precision (Precision between assays) Three samples of known concentration were tested in 16 separate assays to assess inter-assay precision.

Intra-assay Precision

Sample	n	Mean (pg/mL)	SD	CV%
1	8	477.3	14.4	3.0
2	8	125.0	4.5	3.6
3	8	63.0	2.1	3.3

Inter-assay Precision

Sample	n	Mean (pg/mL)	SD	CV%
1	16	495.4	24.9	5.0
2	16	127.8	6.3	4.9
3	16	64.1	3.1	4.8

RECOVERY

The recovery of mouse Adiponectin spiked to three different levels throughout the range of the assay was evaluated.

Sample Type		Average% of Expected	Range (%)
Mouse serum	1:100,000	103	97-108
	1:200,000	99	96-104
Cell culture supernatant	1:8	113	103-123
	1:16	102	96-112
Tissue homogenate	1:400	93	84-101
	1:800	90	87-92

LINEARITY

To assess the linearity of the assay, samples were diluted with the appropriate Sample Diluent to produce samples with values within the dynamic range of the assay. (The mouse serum was initially diluted 1:20,000. The tissue homogenate was initially diluted 1:100. )

		Mouse serum	Cell culture supernatant	Tissue homogenate
1:2	Average% of Expected	100	100	100
	Range (%)	-	-	-
1:4	Average% of Expected	101	108	102
	Range (%)	99-103	103-112	102-103
1:8	Average% of Expected	101	116	104
	Range (%)	100-102	108-124	103-105
1:16	Average% of Expected	105	122	105
	Range (%)	103-108	118-126	99-111

CALIBRATION

This immunoassay is calibrated against a highly purified recombinant mouse Adiponectinin produced at Sunlong Medical™.